DK2875877T3

DK2875877T3 - Method of preparing a profile of varying cross-section

Info

Publication number: DK2875877T3
Application number: DK14003646.8T
Authority: DK
Inventors: Kurt Aigner; Edwin Pfisterer; Martin Schreivogl; Harald Schachinger; Erich Spreitzer
Original assignee: Welser Profile Austria Gmbh
Priority date: 2013-11-05
Filing date: 2014-10-28
Publication date: 2018-07-16
Also published as: EP2875877A1; ES2675794T3; DE202013012608U1; EP3299090A1; DE102013018581B4; EP2875877B1; DE102013018581A1

Description

The present invention relates to a method for producing an elongate profile having a cross section that varies in the longitudinal direction, in which method an elongate metal strip comprising two strip edges is profiled into a semifinished profile in a first profiling process and is subsequently stamped in portions in a second profiling process such that at least two portions are mutually offset in a direction perpendicular to the longitudinal extension of the semifinished profile.

The use of profiles having varying cross sections is required in various technical fields. It is therefore necessary, for example, to introduce a load into the profile at a specific point on the profile. The cross section of the profile must be enlarged at this point, or optionally also in adjacent regions, so that the profile is suitable, in terms of structural mechanics, for receiving the load. It may also be necessary that the cross section is reduced at a specific point, for example in order to attach a specific attachment to this point, for example, or simply to create space for further components that do not necessarily have to be connected to the profile, but instead would collide with the profile. An example of the use of profiles having a varying cross section is the production of automobiles. It is not unusual for specific support profiles to have recesses at specific points for reasons of space, so that cable guides or the like can be guided past the profile at this point, for example. A method for producing an elongate profile having a varying cross section is known from EP 1537922 B1, for example. The method requires, as the starting material, a metal sheet that has a specific shape and is shaped into a closed profile in a plurality of steps by means of a specific roller profiling device.

The roller profiling system must be equipped with specially adjustable rollers for this purpose.

Only continuous cross section changes can be implemented by the method; a more or less abrupt change of the cross section cannot be produced. A method of the type mentioned at the outset is known from EP 1344583 B1, for example. In this method, a profiled strip is initially produced from a flat strip by means of rolling, and this profiled strip is subsequently stamped in portions such that at least two portions are mutually offset in a direction perpendicular to the longitudinal extension of the strip. The profiled strip is trimmed after being stamped such that the mutually offset portions have a different cross section. Different cross sections are therefore produced due to the last method step of trimming.

The method disclosed in EP 1344583 B1 has the disadvantage that trimming the profile may be difficult, in particular in the case of complex profile cross sections. Furthermore, in this method, regions of the starting material are shaped that are subsequently cut away. This requires relatively high amount of shaping effort and may result in unfavourable flow behaviour of the material during the stamping process.

The problem addressed by the present invention is that of improving the method of the type mentioned at the outset and to prevent the problems addressed.

The problem is solved by the features of independent claim 1. Accordingly, the method mentioned at the outset provides a solution according to the invention to the problem if the metal strip is trimmed before the first profiling process such that said strip has a width that varies in the longitudinal direction. The method according to the invention has the advantage that the metal strip can be trimmed right at the beginning of the method such that later trimming is no longer necessary.

Trimming the still unprofiled metal strip is particularly easy and can be carried out both in a punching press and in a rolling mill. A plurality of portions may be mutually offset at regular intervals. For example, the finished profile may be crenellated as a result.

Advantageous embodiments of the present invention are found in the dependent claims.

In a particularly preferred embodiment of the present invention, the metal strip is trimmed such that the strip edges extend continuously in a straight line after the second profiling process. As a result, a U-profile having a varying profile height may be produced, for example, the strip edges on the opening side of the profile extending at a constant level. Strip edges that extend continuously in a straight line may also be desired if the strip edges are further processed, for example, using a subsequent continuous method, for example said strip edges are bent or rolled up or welded together. In order to obtain strip edges that extend continuously in a straight line, the metal strip must be trimmed so as to correspond with the offset. The trimmed metal strip must have a larger width at a point at which the finished profile has more material than at other points.

In another preferred embodiment of the present invention, the metal strip is profiled into an open semifinished profile in a first profiling process. An open semifinished profile can be mutually offset at the desired points in a second profiling process without distortions or wrinkling. The additional method is simplified overall as a result. More particularly preferably, the metal strip is profiled into a U-profile in the first profiling process. Further preferably, the U-profile is stamped in the second profiling process such that the at least two mutually offset portions are mutually offset in a direction perpendicular to the base of the U-profile. The base of the U-profile therefore undergoes a change in level in the second profiling process and can be stepped or crenellated, for example. In the first profiling process, the metal strip may, for example, also be profiled into a pure V-profile or into a V-profile having additionally angled leg ends that extend mutually in parallel. The base of the profile is V-shaped in this case.

In order to increase the stability of the U-profile or V-profile, it may be further provided according to the invention that the U-profile is shaped into a hat profile in a third profiling process following the second profiling process, by the legs of the U-profile or V-profile being bent in the regions of the ends thereof. If the starting material is trimmed, as described above, such that the strip edges extend continuously in a straight line after the second profiling process, a hat profile having a constant width and a varying profile height is produced.

In another preferred embodiment of the present invention, the semifinished profile is shaped into a closed hollow profile in a third profiling process following the second profiling process. A particularly stable hollow profile having a varying profile height is thus obtained. Preferably, the strip edges are welded or soldered so as to be joined together, in particular in order to further increase the stability of the finished profile. The final shaping into a closed hollow profile may be carried out using a cold rolling method, for example.

In a further preferred embodiment of the present invention, the first profiling process is carried out using a cold rolling method. For example, as a result, a U-profile can be produced in a particularly simple manner in the first profiling process. Depending on the material thickness and/or complexity of the semifinished profile to be produced, the first profiling process may be carried out preferably in a plurality of profiling steps. For example, it may be an advantage for the microstructure if a particularly significant change in shape, for example bending by 90°, is carried out in a plurality of steps rather than in one step.

Alternatively, it is conceivable to carry out the first profiling process in any desired press, for example in a hydraulic press. There may also be a plurality of profiling steps. It is particularly advantageous if both the trimming step and the first profiling process are carried out by means of a stamping press using an intermittent method. It is therefore also possible to prefabricate longer profiles in a rapid and cost-effective manner.

In another particularly preferred embodiment of the present invention, the second profiling process is also carried out in a press, and therefore using an intermittent, non-continuous method. Firstly, no change or at least no further change to another profiling device is necessary as a result. Additionally, a particularly large and, if desired, stepped offset can be produced in a press, in particular in a deep drawing press. Alternatively, it is of course possible to carry out the second profiling process using a continuous rolling method. For this purpose, special rollers having shape stamping elements on the outer periphery may preferably be provided.

Irrespective of whether the second profiling process is carried out in a press or in the rolling mill, it is also advantageous in this case if the second profiling process is made up of a plurality of profiling steps, in particular if a particularly large offset is to be produced.

The method according to the invention is particularly suitable for producing metal profiles from a flat, elongate metal strip. Preferably, steel profiles are produced using the method according to the invention.

It should be noted that the length of the profiles can be specified at the beginning of the process, by trimming a correspondingly long metal sheet strip, or after the actual profile production process, by trimming the finished profiles.

The invention is explained in greater detail in the following with reference to drawings, in which:

Fig. 1 shows an elongate profile having a cross section that varies in the longitudinal direction, produced using the method according to the invention,

Fig. 2 shows an elongate metal strip as the starting material for producing the profile from Fig. 1,

Fig. 3 shows the metal strip from Fig. 2 after the trimming process,

Fig. 4 shows the metal strip from Fig. 3 shaped into a U-profile,

Fig. 5 shows the U-profile from Fig. 4 after a further shaping step, having slightly mutually offset portions,

Fig. 6 shows the U-profile from Fig. 5 after a further shaping step, and

Fig. 7 is a schematic view of a pair of rollers for producing the mutually offset portions in a cold rolling mill.

In the following embodiments, like parts are denoted by like reference signs. If there are references signs in an illustration that are not described in greater detail in the associated drawing description, reference is made to previous or subsequent drawing descriptions.

Fig. 1 shows an elongate profile 1 that has been produced using the method according to the invention. The profile is a hat profile, which substantially has the shape of a U-profile having legs 9 that are bent outwards. It can be seen from the drawing that the profile comprises a plurality of portions 4 and 5 which are mutually offset perpendicularly to the longitudinal extension of the profile. The mutually offset portions alternate in the longitudinal direction of the profile.

More precisely, the portions 5 are offset outwards relative to the portions 4 therebetween with regard to the base of the hat profile. The portions 5 therefore protrude outwards in a crenellated form. As the drawing shows, the legs 9 that are bent outwards are not affected by the offset.

The outer edges 3 of the hat profile also extend continuously in a straight line.

The method for producing the profile shown in Fig. 1 is described in more detail in the following. The profile is manufactured from a simple elongate metal strip that preferably consists of steel. The elongate metal strip is shown schematically in Fig. 2 and can be fed into the device for producing the profile, for example by means of a reel from which said strip is unwound. The metal strip may be trimmed to a specific length before the profile is actually produced. As Fig. 2 shows, the metal strip 2 extends in a substantially straight line; the two strip edges 3 of the metal strip are also designed so as to be substantially straight and extend in parallel with one another.

In a first method step, the metal strip is first trimmed such that said strip subsequently has a width that varies in the longitudinal direction. The metal strip is preferably trimmed in the conventional manner in a punching press. The trimmed metal strip 2 is shown in Fig. 3. It can be seen that the two strip edges 3 do not extend continuously in a straight line anymore. Rather, recesses 6 are formed in portions of the strip edges, which recesses are in the region of the portions 4 of the profile shown in Fig. 1 that are to be produced later. The shape of the transition between the recesses and the regions in which the strip edges 3 remain untrimmed depends to a certain extent on how exactly the transition between the mutually offset portions 4 and 5 is to be designed.

The trimmed metal strip 2 is shaped into a simple U-profile in the next method step. The resulting U-profile 10 is shown in Fig. 4. The U-profile comprises a continuously straight base 7 and two legs 8 that protrude from the base at right angles. Shaping into the U-profile is preferably carried out in the line using a cold rolling method and may involve a plurality of shaping steps. In particular, if the material of the metal strip is very thick, it is advisable to bend the legs 8 in steps. The shaping into the U-profile can of course also be carried out by means of another suitable press. For example, it is possible to shape metal strips having a low material thickness into the U-profile in a deep drawing press.

Further shaping follows the shaping into the U-profile, by means of which further shaping the mutually offset portions shown in Fig. 1 are produced. This profiling process can also be carried out in a plurality of profiling steps, which is particularly necessary if two portions of the profile are to be particularly greatly mutually offset. Offsetting preferably takes place in a deep drawing press. Fig. 5 shows the U-profile 10 after a first deep drawing process, in which initially a slight offset is produced between the portions 4 and 5. The drawing shows that the depth of the recesses 6 in the strip edge 3 has already reduced after the first deep drawing process. Fig. 6 shows the same U-profile after a further stamping process. The offset between the two portions 4 and 5 already corresponds to the desired offset. The recesses 6 in the strip edge 3 have now disappeared after the profile has been further offset. The strip edges 3 now extend continuously in a straight line again, just as is the case with the starting material, i.e. the metal strip 2 from Fig. 2.

In order to achieve the finished hat profile shown in Fig. 1, only the ends 9 of the two legs 8 of the hat profile have to be bent outwards by approximately 90° along the bend lines 11 indicated in Fig. 6. This process can similarly be carried out in a simple manner either in a rolling mill or in a press.

Finally, Fig. 7 is another schematic view of a pair of rollers 12/13 for producing the offset between the portions 4 and 5 in a rolling mill. The drawing is a longitudinal section in each case through the pair of rollers and the still-unshaped U-profile 10. In the case shown, the portions 4 offset into the profile interior are produced by the profile base 7 being pressed in. The upper roller 12 of the pair of rollers comprises an outwardly protruding ram 15 on the outer periphery thereof for this purpose. The lower roller 13 has a recess 16 on the outer periphery thereof, with which recess the ram 15 engages. The U-profile is stabilised by a plurality of pairs of rollers (not shown) during the stamping process. The upper roller 12 of the pair of rollers shown comprises a stabilising edge 14, by means of which the relevant leg 8 of the U-profile is stabilised or held during the stamping process.

Claims

A method of producing an oblong profile (1) having a longitudinal cross-section, in which an elongated metal band (2) having two band edges (3) is profiled into a semi-finished profile (10) in a first profiling process, wherein, in another profiling process, the semi-finished profile (10) is subsequently sectioned in such a way that at least two sections (4, 5) are offset to each other in a direction perpendicular to the length of the semi-finished profile (10), characterized in that the metal strip (2) the first profiling process is angled in such a way that it has a width that varies in the longitudinal direction.

Method according to claim 1, characterized in that the metal strip (2) is edged in such a way that the strip edges (3) after the second profiling process proceed in a straight line.

Method according to claim 1 or 2, characterized in that the metal strip (2) is profiled in the first profiling process to an open semi-finished profile (10).

Method according to claim 3, characterized in that in the first profiling process the metal strip (2) is profiled to a U-profile (10) or to a V-profile.

Method according to claim 4, characterized in that the U-profile (10) or V-profile in the second profiling process is embossed in such a way that the at least two offset sections (4, 5) are displaced against one another in a direction perpendicular to the bottom (7) of the U-profile (10) or V-profile.

Method according to claim 5, characterized in that, after the second profiling process in a third profiling process, the U-profile (10) is converted into a top-hat profile (1), the legs of the U-profile (10) or V-profile being bent the area at their ends (9).

Process according to one of Claims 1 to 5, characterized in that, after the second profiling process, in the third profiling process, the semi-finished profile (10) is converted into a closed top cap profile.

Method according to claim 7, characterized in that the band edges (3) are subsequently welded or soldered together.

Process according to one of claims 1 to 8, characterized in that the first profiling process takes place in a cold rolling process.

Method according to one of claims 1 to 9, characterized in that the second profiling process takes place in a pressing device.